| /* |
| * Copyright (c) 2016-present, Yann Collet, Facebook, Inc. |
| * All rights reserved. |
| * |
| * This source code is licensed under both the BSD-style license (found in the |
| * LICENSE file in the root directory of this source tree) and the GPLv2 (found |
| * in the COPYING file in the root directory of this source tree). |
| * You may select, at your option, one of the above-listed licenses. |
| */ |
| |
| /* zstd_decompress_block : |
| * this module takes care of decompressing _compressed_ block */ |
| |
| /*-******************************************************* |
| * Dependencies |
| *********************************************************/ |
| #include <string.h> /* memcpy, memmove, memset */ |
| #include "compiler.h" /* prefetch */ |
| #include "cpu.h" /* bmi2 */ |
| #include "mem.h" /* low level memory routines */ |
| #define FSE_STATIC_LINKING_ONLY |
| #include "fse.h" |
| #define HUF_STATIC_LINKING_ONLY |
| #include "huf.h" |
| #include "zstd_internal.h" |
| #include "zstd_decompress_internal.h" /* ZSTD_DCtx */ |
| #include "zstd_ddict.h" /* ZSTD_DDictDictContent */ |
| #include "zstd_decompress_block.h" |
| |
| /*_******************************************************* |
| * Macros |
| **********************************************************/ |
| |
| /* These two optional macros force the use one way or another of the two |
| * ZSTD_decompressSequences implementations. You can't force in both directions |
| * at the same time. |
| */ |
| #if defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \ |
| defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG) |
| #error "Cannot force the use of the short and the long ZSTD_decompressSequences variants!" |
| #endif |
| |
| |
| /*_******************************************************* |
| * Memory operations |
| **********************************************************/ |
| static void ZSTD_copy4(void* dst, const void* src) { memcpy(dst, src, 4); } |
| |
| |
| /*-************************************************************* |
| * Block decoding |
| ***************************************************************/ |
| |
| /*! ZSTD_getcBlockSize() : |
| * Provides the size of compressed block from block header `src` */ |
| size_t ZSTD_getcBlockSize(const void* src, size_t srcSize, |
| blockProperties_t* bpPtr) |
| { |
| RETURN_ERROR_IF(srcSize < ZSTD_blockHeaderSize, srcSize_wrong); |
| |
| { U32 const cBlockHeader = MEM_readLE24(src); |
| U32 const cSize = cBlockHeader >> 3; |
| bpPtr->lastBlock = cBlockHeader & 1; |
| bpPtr->blockType = (blockType_e)((cBlockHeader >> 1) & 3); |
| bpPtr->origSize = cSize; /* only useful for RLE */ |
| if (bpPtr->blockType == bt_rle) return 1; |
| RETURN_ERROR_IF(bpPtr->blockType == bt_reserved, corruption_detected); |
| return cSize; |
| } |
| } |
| |
| |
| /* Hidden declaration for fullbench */ |
| size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx, |
| const void* src, size_t srcSize); |
| /*! ZSTD_decodeLiteralsBlock() : |
| * @return : nb of bytes read from src (< srcSize ) |
| * note : symbol not declared but exposed for fullbench */ |
| size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx, |
| const void* src, size_t srcSize) /* note : srcSize < BLOCKSIZE */ |
| { |
| RETURN_ERROR_IF(srcSize < MIN_CBLOCK_SIZE, corruption_detected); |
| |
| { const BYTE* const istart = (const BYTE*) src; |
| symbolEncodingType_e const litEncType = (symbolEncodingType_e)(istart[0] & 3); |
| |
| switch(litEncType) |
| { |
| case set_repeat: |
| RETURN_ERROR_IF(dctx->litEntropy==0, dictionary_corrupted); |
| /* fall-through */ |
| |
| case set_compressed: |
| RETURN_ERROR_IF(srcSize < 5, corruption_detected, "srcSize >= MIN_CBLOCK_SIZE == 3; here we need up to 5 for case 3"); |
| { size_t lhSize, litSize, litCSize; |
| U32 singleStream=0; |
| U32 const lhlCode = (istart[0] >> 2) & 3; |
| U32 const lhc = MEM_readLE32(istart); |
| size_t hufSuccess; |
| switch(lhlCode) |
| { |
| case 0: case 1: default: /* note : default is impossible, since lhlCode into [0..3] */ |
| /* 2 - 2 - 10 - 10 */ |
| singleStream = !lhlCode; |
| lhSize = 3; |
| litSize = (lhc >> 4) & 0x3FF; |
| litCSize = (lhc >> 14) & 0x3FF; |
| break; |
| case 2: |
| /* 2 - 2 - 14 - 14 */ |
| lhSize = 4; |
| litSize = (lhc >> 4) & 0x3FFF; |
| litCSize = lhc >> 18; |
| break; |
| case 3: |
| /* 2 - 2 - 18 - 18 */ |
| lhSize = 5; |
| litSize = (lhc >> 4) & 0x3FFFF; |
| litCSize = (lhc >> 22) + (istart[4] << 10); |
| break; |
| } |
| RETURN_ERROR_IF(litSize > ZSTD_BLOCKSIZE_MAX, corruption_detected); |
| RETURN_ERROR_IF(litCSize + lhSize > srcSize, corruption_detected); |
| |
| /* prefetch huffman table if cold */ |
| if (dctx->ddictIsCold && (litSize > 768 /* heuristic */)) { |
| PREFETCH_AREA(dctx->HUFptr, sizeof(dctx->entropy.hufTable)); |
| } |
| |
| if (litEncType==set_repeat) { |
| if (singleStream) { |
| hufSuccess = HUF_decompress1X_usingDTable_bmi2( |
| dctx->litBuffer, litSize, istart+lhSize, litCSize, |
| dctx->HUFptr, dctx->bmi2); |
| } else { |
| hufSuccess = HUF_decompress4X_usingDTable_bmi2( |
| dctx->litBuffer, litSize, istart+lhSize, litCSize, |
| dctx->HUFptr, dctx->bmi2); |
| } |
| } else { |
| if (singleStream) { |
| #if defined(HUF_FORCE_DECOMPRESS_X2) |
| hufSuccess = HUF_decompress1X_DCtx_wksp( |
| dctx->entropy.hufTable, dctx->litBuffer, litSize, |
| istart+lhSize, litCSize, dctx->workspace, |
| sizeof(dctx->workspace)); |
| #else |
| hufSuccess = HUF_decompress1X1_DCtx_wksp_bmi2( |
| dctx->entropy.hufTable, dctx->litBuffer, litSize, |
| istart+lhSize, litCSize, dctx->workspace, |
| sizeof(dctx->workspace), dctx->bmi2); |
| #endif |
| } else { |
| hufSuccess = HUF_decompress4X_hufOnly_wksp_bmi2( |
| dctx->entropy.hufTable, dctx->litBuffer, litSize, |
| istart+lhSize, litCSize, dctx->workspace, |
| sizeof(dctx->workspace), dctx->bmi2); |
| } |
| } |
| |
| RETURN_ERROR_IF(HUF_isError(hufSuccess), corruption_detected); |
| |
| dctx->litPtr = dctx->litBuffer; |
| dctx->litSize = litSize; |
| dctx->litEntropy = 1; |
| if (litEncType==set_compressed) dctx->HUFptr = dctx->entropy.hufTable; |
| memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH); |
| return litCSize + lhSize; |
| } |
| |
| case set_basic: |
| { size_t litSize, lhSize; |
| U32 const lhlCode = ((istart[0]) >> 2) & 3; |
| switch(lhlCode) |
| { |
| case 0: case 2: default: /* note : default is impossible, since lhlCode into [0..3] */ |
| lhSize = 1; |
| litSize = istart[0] >> 3; |
| break; |
| case 1: |
| lhSize = 2; |
| litSize = MEM_readLE16(istart) >> 4; |
| break; |
| case 3: |
| lhSize = 3; |
| litSize = MEM_readLE24(istart) >> 4; |
| break; |
| } |
| |
| if (lhSize+litSize+WILDCOPY_OVERLENGTH > srcSize) { /* risk reading beyond src buffer with wildcopy */ |
| RETURN_ERROR_IF(litSize+lhSize > srcSize, corruption_detected); |
| memcpy(dctx->litBuffer, istart+lhSize, litSize); |
| dctx->litPtr = dctx->litBuffer; |
| dctx->litSize = litSize; |
| memset(dctx->litBuffer + dctx->litSize, 0, WILDCOPY_OVERLENGTH); |
| return lhSize+litSize; |
| } |
| /* direct reference into compressed stream */ |
| dctx->litPtr = istart+lhSize; |
| dctx->litSize = litSize; |
| return lhSize+litSize; |
| } |
| |
| case set_rle: |
| { U32 const lhlCode = ((istart[0]) >> 2) & 3; |
| size_t litSize, lhSize; |
| switch(lhlCode) |
| { |
| case 0: case 2: default: /* note : default is impossible, since lhlCode into [0..3] */ |
| lhSize = 1; |
| litSize = istart[0] >> 3; |
| break; |
| case 1: |
| lhSize = 2; |
| litSize = MEM_readLE16(istart) >> 4; |
| break; |
| case 3: |
| lhSize = 3; |
| litSize = MEM_readLE24(istart) >> 4; |
| RETURN_ERROR_IF(srcSize<4, corruption_detected, "srcSize >= MIN_CBLOCK_SIZE == 3; here we need lhSize+1 = 4"); |
| break; |
| } |
| RETURN_ERROR_IF(litSize > ZSTD_BLOCKSIZE_MAX, corruption_detected); |
| memset(dctx->litBuffer, istart[lhSize], litSize + WILDCOPY_OVERLENGTH); |
| dctx->litPtr = dctx->litBuffer; |
| dctx->litSize = litSize; |
| return lhSize+1; |
| } |
| default: |
| RETURN_ERROR(corruption_detected, "impossible"); |
| } |
| } |
| } |
| |
| /* Default FSE distribution tables. |
| * These are pre-calculated FSE decoding tables using default distributions as defined in specification : |
| * https://github.com/facebook/zstd/blob/master/doc/zstd_compression_format.md#default-distributions |
| * They were generated programmatically with following method : |
| * - start from default distributions, present in /lib/common/zstd_internal.h |
| * - generate tables normally, using ZSTD_buildFSETable() |
| * - printout the content of tables |
| * - pretify output, report below, test with fuzzer to ensure it's correct */ |
| |
| /* Default FSE distribution table for Literal Lengths */ |
| static const ZSTD_seqSymbol LL_defaultDTable[(1<<LL_DEFAULTNORMLOG)+1] = { |
| { 1, 1, 1, LL_DEFAULTNORMLOG}, /* header : fastMode, tableLog */ |
| /* nextState, nbAddBits, nbBits, baseVal */ |
| { 0, 0, 4, 0}, { 16, 0, 4, 0}, |
| { 32, 0, 5, 1}, { 0, 0, 5, 3}, |
| { 0, 0, 5, 4}, { 0, 0, 5, 6}, |
| { 0, 0, 5, 7}, { 0, 0, 5, 9}, |
| { 0, 0, 5, 10}, { 0, 0, 5, 12}, |
| { 0, 0, 6, 14}, { 0, 1, 5, 16}, |
| { 0, 1, 5, 20}, { 0, 1, 5, 22}, |
| { 0, 2, 5, 28}, { 0, 3, 5, 32}, |
| { 0, 4, 5, 48}, { 32, 6, 5, 64}, |
| { 0, 7, 5, 128}, { 0, 8, 6, 256}, |
| { 0, 10, 6, 1024}, { 0, 12, 6, 4096}, |
| { 32, 0, 4, 0}, { 0, 0, 4, 1}, |
| { 0, 0, 5, 2}, { 32, 0, 5, 4}, |
| { 0, 0, 5, 5}, { 32, 0, 5, 7}, |
| { 0, 0, 5, 8}, { 32, 0, 5, 10}, |
| { 0, 0, 5, 11}, { 0, 0, 6, 13}, |
| { 32, 1, 5, 16}, { 0, 1, 5, 18}, |
| { 32, 1, 5, 22}, { 0, 2, 5, 24}, |
| { 32, 3, 5, 32}, { 0, 3, 5, 40}, |
| { 0, 6, 4, 64}, { 16, 6, 4, 64}, |
| { 32, 7, 5, 128}, { 0, 9, 6, 512}, |
| { 0, 11, 6, 2048}, { 48, 0, 4, 0}, |
| { 16, 0, 4, 1}, { 32, 0, 5, 2}, |
| { 32, 0, 5, 3}, { 32, 0, 5, 5}, |
| { 32, 0, 5, 6}, { 32, 0, 5, 8}, |
| { 32, 0, 5, 9}, { 32, 0, 5, 11}, |
| { 32, 0, 5, 12}, { 0, 0, 6, 15}, |
| { 32, 1, 5, 18}, { 32, 1, 5, 20}, |
| { 32, 2, 5, 24}, { 32, 2, 5, 28}, |
| { 32, 3, 5, 40}, { 32, 4, 5, 48}, |
| { 0, 16, 6,65536}, { 0, 15, 6,32768}, |
| { 0, 14, 6,16384}, { 0, 13, 6, 8192}, |
| }; /* LL_defaultDTable */ |
| |
| /* Default FSE distribution table for Offset Codes */ |
| static const ZSTD_seqSymbol OF_defaultDTable[(1<<OF_DEFAULTNORMLOG)+1] = { |
| { 1, 1, 1, OF_DEFAULTNORMLOG}, /* header : fastMode, tableLog */ |
| /* nextState, nbAddBits, nbBits, baseVal */ |
| { 0, 0, 5, 0}, { 0, 6, 4, 61}, |
| { 0, 9, 5, 509}, { 0, 15, 5,32765}, |
| { 0, 21, 5,2097149}, { 0, 3, 5, 5}, |
| { 0, 7, 4, 125}, { 0, 12, 5, 4093}, |
| { 0, 18, 5,262141}, { 0, 23, 5,8388605}, |
| { 0, 5, 5, 29}, { 0, 8, 4, 253}, |
| { 0, 14, 5,16381}, { 0, 20, 5,1048573}, |
| { 0, 2, 5, 1}, { 16, 7, 4, 125}, |
| { 0, 11, 5, 2045}, { 0, 17, 5,131069}, |
| { 0, 22, 5,4194301}, { 0, 4, 5, 13}, |
| { 16, 8, 4, 253}, { 0, 13, 5, 8189}, |
| { 0, 19, 5,524285}, { 0, 1, 5, 1}, |
| { 16, 6, 4, 61}, { 0, 10, 5, 1021}, |
| { 0, 16, 5,65533}, { 0, 28, 5,268435453}, |
| { 0, 27, 5,134217725}, { 0, 26, 5,67108861}, |
| { 0, 25, 5,33554429}, { 0, 24, 5,16777213}, |
| }; /* OF_defaultDTable */ |
| |
| |
| /* Default FSE distribution table for Match Lengths */ |
| static const ZSTD_seqSymbol ML_defaultDTable[(1<<ML_DEFAULTNORMLOG)+1] = { |
| { 1, 1, 1, ML_DEFAULTNORMLOG}, /* header : fastMode, tableLog */ |
| /* nextState, nbAddBits, nbBits, baseVal */ |
| { 0, 0, 6, 3}, { 0, 0, 4, 4}, |
| { 32, 0, 5, 5}, { 0, 0, 5, 6}, |
| { 0, 0, 5, 8}, { 0, 0, 5, 9}, |
| { 0, 0, 5, 11}, { 0, 0, 6, 13}, |
| { 0, 0, 6, 16}, { 0, 0, 6, 19}, |
| { 0, 0, 6, 22}, { 0, 0, 6, 25}, |
| { 0, 0, 6, 28}, { 0, 0, 6, 31}, |
| { 0, 0, 6, 34}, { 0, 1, 6, 37}, |
| { 0, 1, 6, 41}, { 0, 2, 6, 47}, |
| { 0, 3, 6, 59}, { 0, 4, 6, 83}, |
| { 0, 7, 6, 131}, { 0, 9, 6, 515}, |
| { 16, 0, 4, 4}, { 0, 0, 4, 5}, |
| { 32, 0, 5, 6}, { 0, 0, 5, 7}, |
| { 32, 0, 5, 9}, { 0, 0, 5, 10}, |
| { 0, 0, 6, 12}, { 0, 0, 6, 15}, |
| { 0, 0, 6, 18}, { 0, 0, 6, 21}, |
| { 0, 0, 6, 24}, { 0, 0, 6, 27}, |
| { 0, 0, 6, 30}, { 0, 0, 6, 33}, |
| { 0, 1, 6, 35}, { 0, 1, 6, 39}, |
| { 0, 2, 6, 43}, { 0, 3, 6, 51}, |
| { 0, 4, 6, 67}, { 0, 5, 6, 99}, |
| { 0, 8, 6, 259}, { 32, 0, 4, 4}, |
| { 48, 0, 4, 4}, { 16, 0, 4, 5}, |
| { 32, 0, 5, 7}, { 32, 0, 5, 8}, |
| { 32, 0, 5, 10}, { 32, 0, 5, 11}, |
| { 0, 0, 6, 14}, { 0, 0, 6, 17}, |
| { 0, 0, 6, 20}, { 0, 0, 6, 23}, |
| { 0, 0, 6, 26}, { 0, 0, 6, 29}, |
| { 0, 0, 6, 32}, { 0, 16, 6,65539}, |
| { 0, 15, 6,32771}, { 0, 14, 6,16387}, |
| { 0, 13, 6, 8195}, { 0, 12, 6, 4099}, |
| { 0, 11, 6, 2051}, { 0, 10, 6, 1027}, |
| }; /* ML_defaultDTable */ |
| |
| |
| static void ZSTD_buildSeqTable_rle(ZSTD_seqSymbol* dt, U32 baseValue, U32 nbAddBits) |
| { |
| void* ptr = dt; |
| ZSTD_seqSymbol_header* const DTableH = (ZSTD_seqSymbol_header*)ptr; |
| ZSTD_seqSymbol* const cell = dt + 1; |
| |
| DTableH->tableLog = 0; |
| DTableH->fastMode = 0; |
| |
| cell->nbBits = 0; |
| cell->nextState = 0; |
| assert(nbAddBits < 255); |
| cell->nbAdditionalBits = (BYTE)nbAddBits; |
| cell->baseValue = baseValue; |
| } |
| |
| |
| /* ZSTD_buildFSETable() : |
| * generate FSE decoding table for one symbol (ll, ml or off) |
| * cannot fail if input is valid => |
| * all inputs are presumed validated at this stage */ |
| void |
| ZSTD_buildFSETable(ZSTD_seqSymbol* dt, |
| const short* normalizedCounter, unsigned maxSymbolValue, |
| const U32* baseValue, const U32* nbAdditionalBits, |
| unsigned tableLog) |
| { |
| ZSTD_seqSymbol* const tableDecode = dt+1; |
| U16 symbolNext[MaxSeq+1]; |
| |
| U32 const maxSV1 = maxSymbolValue + 1; |
| U32 const tableSize = 1 << tableLog; |
| U32 highThreshold = tableSize-1; |
| |
| /* Sanity Checks */ |
| assert(maxSymbolValue <= MaxSeq); |
| assert(tableLog <= MaxFSELog); |
| |
| /* Init, lay down lowprob symbols */ |
| { ZSTD_seqSymbol_header DTableH; |
| DTableH.tableLog = tableLog; |
| DTableH.fastMode = 1; |
| { S16 const largeLimit= (S16)(1 << (tableLog-1)); |
| U32 s; |
| for (s=0; s<maxSV1; s++) { |
| if (normalizedCounter[s]==-1) { |
| tableDecode[highThreshold--].baseValue = s; |
| symbolNext[s] = 1; |
| } else { |
| if (normalizedCounter[s] >= largeLimit) DTableH.fastMode=0; |
| symbolNext[s] = normalizedCounter[s]; |
| } } } |
| memcpy(dt, &DTableH, sizeof(DTableH)); |
| } |
| |
| /* Spread symbols */ |
| { U32 const tableMask = tableSize-1; |
| U32 const step = FSE_TABLESTEP(tableSize); |
| U32 s, position = 0; |
| for (s=0; s<maxSV1; s++) { |
| int i; |
| for (i=0; i<normalizedCounter[s]; i++) { |
| tableDecode[position].baseValue = s; |
| position = (position + step) & tableMask; |
| while (position > highThreshold) position = (position + step) & tableMask; /* lowprob area */ |
| } } |
| assert(position == 0); /* position must reach all cells once, otherwise normalizedCounter is incorrect */ |
| } |
| |
| /* Build Decoding table */ |
| { U32 u; |
| for (u=0; u<tableSize; u++) { |
| U32 const symbol = tableDecode[u].baseValue; |
| U32 const nextState = symbolNext[symbol]++; |
| tableDecode[u].nbBits = (BYTE) (tableLog - BIT_highbit32(nextState) ); |
| tableDecode[u].nextState = (U16) ( (nextState << tableDecode[u].nbBits) - tableSize); |
| assert(nbAdditionalBits[symbol] < 255); |
| tableDecode[u].nbAdditionalBits = (BYTE)nbAdditionalBits[symbol]; |
| tableDecode[u].baseValue = baseValue[symbol]; |
| } } |
| } |
| |
| |
| /*! ZSTD_buildSeqTable() : |
| * @return : nb bytes read from src, |
| * or an error code if it fails */ |
| static size_t ZSTD_buildSeqTable(ZSTD_seqSymbol* DTableSpace, const ZSTD_seqSymbol** DTablePtr, |
| symbolEncodingType_e type, unsigned max, U32 maxLog, |
| const void* src, size_t srcSize, |
| const U32* baseValue, const U32* nbAdditionalBits, |
| const ZSTD_seqSymbol* defaultTable, U32 flagRepeatTable, |
| int ddictIsCold, int nbSeq) |
| { |
| switch(type) |
| { |
| case set_rle : |
| RETURN_ERROR_IF(!srcSize, srcSize_wrong); |
| RETURN_ERROR_IF((*(const BYTE*)src) > max, corruption_detected); |
| { U32 const symbol = *(const BYTE*)src; |
| U32 const baseline = baseValue[symbol]; |
| U32 const nbBits = nbAdditionalBits[symbol]; |
| ZSTD_buildSeqTable_rle(DTableSpace, baseline, nbBits); |
| } |
| *DTablePtr = DTableSpace; |
| return 1; |
| case set_basic : |
| *DTablePtr = defaultTable; |
| return 0; |
| case set_repeat: |
| RETURN_ERROR_IF(!flagRepeatTable, corruption_detected); |
| /* prefetch FSE table if used */ |
| if (ddictIsCold && (nbSeq > 24 /* heuristic */)) { |
| const void* const pStart = *DTablePtr; |
| size_t const pSize = sizeof(ZSTD_seqSymbol) * (SEQSYMBOL_TABLE_SIZE(maxLog)); |
| PREFETCH_AREA(pStart, pSize); |
| } |
| return 0; |
| case set_compressed : |
| { unsigned tableLog; |
| S16 norm[MaxSeq+1]; |
| size_t const headerSize = FSE_readNCount(norm, &max, &tableLog, src, srcSize); |
| RETURN_ERROR_IF(FSE_isError(headerSize), corruption_detected); |
| RETURN_ERROR_IF(tableLog > maxLog, corruption_detected); |
| ZSTD_buildFSETable(DTableSpace, norm, max, baseValue, nbAdditionalBits, tableLog); |
| *DTablePtr = DTableSpace; |
| return headerSize; |
| } |
| default : |
| assert(0); |
| RETURN_ERROR(GENERIC, "impossible"); |
| } |
| } |
| |
| size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr, |
| const void* src, size_t srcSize) |
| { |
| const BYTE* const istart = (const BYTE* const)src; |
| const BYTE* const iend = istart + srcSize; |
| const BYTE* ip = istart; |
| int nbSeq; |
| DEBUGLOG(5, "ZSTD_decodeSeqHeaders"); |
| |
| /* check */ |
| RETURN_ERROR_IF(srcSize < MIN_SEQUENCES_SIZE, srcSize_wrong); |
| |
| /* SeqHead */ |
| nbSeq = *ip++; |
| if (!nbSeq) { |
| *nbSeqPtr=0; |
| RETURN_ERROR_IF(srcSize != 1, srcSize_wrong); |
| return 1; |
| } |
| if (nbSeq > 0x7F) { |
| if (nbSeq == 0xFF) { |
| RETURN_ERROR_IF(ip+2 > iend, srcSize_wrong); |
| nbSeq = MEM_readLE16(ip) + LONGNBSEQ, ip+=2; |
| } else { |
| RETURN_ERROR_IF(ip >= iend, srcSize_wrong); |
| nbSeq = ((nbSeq-0x80)<<8) + *ip++; |
| } |
| } |
| *nbSeqPtr = nbSeq; |
| |
| /* FSE table descriptors */ |
| RETURN_ERROR_IF(ip+4 > iend, srcSize_wrong); /* minimum possible size */ |
| { symbolEncodingType_e const LLtype = (symbolEncodingType_e)(*ip >> 6); |
| symbolEncodingType_e const OFtype = (symbolEncodingType_e)((*ip >> 4) & 3); |
| symbolEncodingType_e const MLtype = (symbolEncodingType_e)((*ip >> 2) & 3); |
| ip++; |
| |
| /* Build DTables */ |
| { size_t const llhSize = ZSTD_buildSeqTable(dctx->entropy.LLTable, &dctx->LLTptr, |
| LLtype, MaxLL, LLFSELog, |
| ip, iend-ip, |
| LL_base, LL_bits, |
| LL_defaultDTable, dctx->fseEntropy, |
| dctx->ddictIsCold, nbSeq); |
| RETURN_ERROR_IF(ZSTD_isError(llhSize), corruption_detected); |
| ip += llhSize; |
| } |
| |
| { size_t const ofhSize = ZSTD_buildSeqTable(dctx->entropy.OFTable, &dctx->OFTptr, |
| OFtype, MaxOff, OffFSELog, |
| ip, iend-ip, |
| OF_base, OF_bits, |
| OF_defaultDTable, dctx->fseEntropy, |
| dctx->ddictIsCold, nbSeq); |
| RETURN_ERROR_IF(ZSTD_isError(ofhSize), corruption_detected); |
| ip += ofhSize; |
| } |
| |
| { size_t const mlhSize = ZSTD_buildSeqTable(dctx->entropy.MLTable, &dctx->MLTptr, |
| MLtype, MaxML, MLFSELog, |
| ip, iend-ip, |
| ML_base, ML_bits, |
| ML_defaultDTable, dctx->fseEntropy, |
| dctx->ddictIsCold, nbSeq); |
| RETURN_ERROR_IF(ZSTD_isError(mlhSize), corruption_detected); |
| ip += mlhSize; |
| } |
| } |
| |
| return ip-istart; |
| } |
| |
| |
| typedef struct { |
| size_t litLength; |
| size_t matchLength; |
| size_t offset; |
| const BYTE* match; |
| } seq_t; |
| |
| typedef struct { |
| size_t state; |
| const ZSTD_seqSymbol* table; |
| } ZSTD_fseState; |
| |
| typedef struct { |
| BIT_DStream_t DStream; |
| ZSTD_fseState stateLL; |
| ZSTD_fseState stateOffb; |
| ZSTD_fseState stateML; |
| size_t prevOffset[ZSTD_REP_NUM]; |
| const BYTE* prefixStart; |
| const BYTE* dictEnd; |
| size_t pos; |
| } seqState_t; |
| |
| |
| /* ZSTD_execSequenceLast7(): |
| * exceptional case : decompress a match starting within last 7 bytes of output buffer. |
| * requires more careful checks, to ensure there is no overflow. |
| * performance does not matter though. |
| * note : this case is supposed to be never generated "naturally" by reference encoder, |
| * since in most cases it needs at least 8 bytes to look for a match. |
| * but it's allowed by the specification. */ |
| FORCE_NOINLINE |
| size_t ZSTD_execSequenceLast7(BYTE* op, |
| BYTE* const oend, seq_t sequence, |
| const BYTE** litPtr, const BYTE* const litLimit, |
| const BYTE* const base, const BYTE* const vBase, const BYTE* const dictEnd) |
| { |
| BYTE* const oLitEnd = op + sequence.litLength; |
| size_t const sequenceLength = sequence.litLength + sequence.matchLength; |
| BYTE* const oMatchEnd = op + sequenceLength; /* risk : address space overflow (32-bits) */ |
| const BYTE* const iLitEnd = *litPtr + sequence.litLength; |
| const BYTE* match = oLitEnd - sequence.offset; |
| |
| /* check */ |
| RETURN_ERROR_IF(oMatchEnd>oend, dstSize_tooSmall, "last match must fit within dstBuffer"); |
| RETURN_ERROR_IF(iLitEnd > litLimit, corruption_detected, "try to read beyond literal buffer"); |
| |
| /* copy literals */ |
| while (op < oLitEnd) *op++ = *(*litPtr)++; |
| |
| /* copy Match */ |
| if (sequence.offset > (size_t)(oLitEnd - base)) { |
| /* offset beyond prefix */ |
| RETURN_ERROR_IF(sequence.offset > (size_t)(oLitEnd - vBase),corruption_detected); |
| match = dictEnd - (base-match); |
| if (match + sequence.matchLength <= dictEnd) { |
| memmove(oLitEnd, match, sequence.matchLength); |
| return sequenceLength; |
| } |
| /* span extDict & currentPrefixSegment */ |
| { size_t const length1 = dictEnd - match; |
| memmove(oLitEnd, match, length1); |
| op = oLitEnd + length1; |
| sequence.matchLength -= length1; |
| match = base; |
| } } |
| while (op < oMatchEnd) *op++ = *match++; |
| return sequenceLength; |
| } |
| |
| |
| HINT_INLINE |
| size_t ZSTD_execSequence(BYTE* op, |
| BYTE* const oend, seq_t sequence, |
| const BYTE** litPtr, const BYTE* const litLimit, |
| const BYTE* const prefixStart, const BYTE* const virtualStart, const BYTE* const dictEnd) |
| { |
| BYTE* const oLitEnd = op + sequence.litLength; |
| size_t const sequenceLength = sequence.litLength + sequence.matchLength; |
| BYTE* const oMatchEnd = op + sequenceLength; /* risk : address space overflow (32-bits) */ |
| BYTE* const oend_w = oend - WILDCOPY_OVERLENGTH; |
| const BYTE* const iLitEnd = *litPtr + sequence.litLength; |
| const BYTE* match = oLitEnd - sequence.offset; |
| |
| /* check */ |
| RETURN_ERROR_IF(oMatchEnd>oend, dstSize_tooSmall, "last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend"); |
| RETURN_ERROR_IF(iLitEnd > litLimit, corruption_detected, "over-read beyond lit buffer"); |
| if (oLitEnd>oend_w) return ZSTD_execSequenceLast7(op, oend, sequence, litPtr, litLimit, prefixStart, virtualStart, dictEnd); |
| |
| /* copy Literals */ |
| ZSTD_copy8(op, *litPtr); |
| if (sequence.litLength > 8) |
| ZSTD_wildcopy(op+8, (*litPtr)+8, sequence.litLength - 8); /* note : since oLitEnd <= oend-WILDCOPY_OVERLENGTH, no risk of overwrite beyond oend */ |
| op = oLitEnd; |
| *litPtr = iLitEnd; /* update for next sequence */ |
| |
| /* copy Match */ |
| if (sequence.offset > (size_t)(oLitEnd - prefixStart)) { |
| /* offset beyond prefix -> go into extDict */ |
| RETURN_ERROR_IF(sequence.offset > (size_t)(oLitEnd - virtualStart), corruption_detected); |
| match = dictEnd + (match - prefixStart); |
| if (match + sequence.matchLength <= dictEnd) { |
| memmove(oLitEnd, match, sequence.matchLength); |
| return sequenceLength; |
| } |
| /* span extDict & currentPrefixSegment */ |
| { size_t const length1 = dictEnd - match; |
| memmove(oLitEnd, match, length1); |
| op = oLitEnd + length1; |
| sequence.matchLength -= length1; |
| match = prefixStart; |
| if (op > oend_w || sequence.matchLength < MINMATCH) { |
| U32 i; |
| for (i = 0; i < sequence.matchLength; ++i) op[i] = match[i]; |
| return sequenceLength; |
| } |
| } } |
| /* Requirement: op <= oend_w && sequence.matchLength >= MINMATCH */ |
| |
| /* match within prefix */ |
| if (sequence.offset < 8) { |
| /* close range match, overlap */ |
| static const U32 dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 }; /* added */ |
| static const int dec64table[] = { 8, 8, 8, 7, 8, 9,10,11 }; /* subtracted */ |
| int const sub2 = dec64table[sequence.offset]; |
| op[0] = match[0]; |
| op[1] = match[1]; |
| op[2] = match[2]; |
| op[3] = match[3]; |
| match += dec32table[sequence.offset]; |
| ZSTD_copy4(op+4, match); |
| match -= sub2; |
| } else { |
| ZSTD_copy8(op, match); |
| } |
| op += 8; match += 8; |
| |
| if (oMatchEnd > oend-(16-MINMATCH)) { |
| if (op < oend_w) { |
| ZSTD_wildcopy(op, match, oend_w - op); |
| match += oend_w - op; |
| op = oend_w; |
| } |
| while (op < oMatchEnd) *op++ = *match++; |
| } else { |
| ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8); /* works even if matchLength < 8 */ |
| } |
| return sequenceLength; |
| } |
| |
| |
| HINT_INLINE |
| size_t ZSTD_execSequenceLong(BYTE* op, |
| BYTE* const oend, seq_t sequence, |
| const BYTE** litPtr, const BYTE* const litLimit, |
| const BYTE* const prefixStart, const BYTE* const dictStart, const BYTE* const dictEnd) |
| { |
| BYTE* const oLitEnd = op + sequence.litLength; |
| size_t const sequenceLength = sequence.litLength + sequence.matchLength; |
| BYTE* const oMatchEnd = op + sequenceLength; /* risk : address space overflow (32-bits) */ |
| BYTE* const oend_w = oend - WILDCOPY_OVERLENGTH; |
| const BYTE* const iLitEnd = *litPtr + sequence.litLength; |
| const BYTE* match = sequence.match; |
| |
| /* check */ |
| RETURN_ERROR_IF(oMatchEnd > oend, dstSize_tooSmall, "last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend"); |
| RETURN_ERROR_IF(iLitEnd > litLimit, corruption_detected, "over-read beyond lit buffer"); |
| if (oLitEnd > oend_w) return ZSTD_execSequenceLast7(op, oend, sequence, litPtr, litLimit, prefixStart, dictStart, dictEnd); |
| |
| /* copy Literals */ |
| ZSTD_copy8(op, *litPtr); /* note : op <= oLitEnd <= oend_w == oend - 8 */ |
| if (sequence.litLength > 8) |
| ZSTD_wildcopy(op+8, (*litPtr)+8, sequence.litLength - 8); /* note : since oLitEnd <= oend-WILDCOPY_OVERLENGTH, no risk of overwrite beyond oend */ |
| op = oLitEnd; |
| *litPtr = iLitEnd; /* update for next sequence */ |
| |
| /* copy Match */ |
| if (sequence.offset > (size_t)(oLitEnd - prefixStart)) { |
| /* offset beyond prefix */ |
| RETURN_ERROR_IF(sequence.offset > (size_t)(oLitEnd - dictStart), corruption_detected); |
| if (match + sequence.matchLength <= dictEnd) { |
| memmove(oLitEnd, match, sequence.matchLength); |
| return sequenceLength; |
| } |
| /* span extDict & currentPrefixSegment */ |
| { size_t const length1 = dictEnd - match; |
| memmove(oLitEnd, match, length1); |
| op = oLitEnd + length1; |
| sequence.matchLength -= length1; |
| match = prefixStart; |
| if (op > oend_w || sequence.matchLength < MINMATCH) { |
| U32 i; |
| for (i = 0; i < sequence.matchLength; ++i) op[i] = match[i]; |
| return sequenceLength; |
| } |
| } } |
| assert(op <= oend_w); |
| assert(sequence.matchLength >= MINMATCH); |
| |
| /* match within prefix */ |
| if (sequence.offset < 8) { |
| /* close range match, overlap */ |
| static const U32 dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 }; /* added */ |
| static const int dec64table[] = { 8, 8, 8, 7, 8, 9,10,11 }; /* subtracted */ |
| int const sub2 = dec64table[sequence.offset]; |
| op[0] = match[0]; |
| op[1] = match[1]; |
| op[2] = match[2]; |
| op[3] = match[3]; |
| match += dec32table[sequence.offset]; |
| ZSTD_copy4(op+4, match); |
| match -= sub2; |
| } else { |
| ZSTD_copy8(op, match); |
| } |
| op += 8; match += 8; |
| |
| if (oMatchEnd > oend-(16-MINMATCH)) { |
| if (op < oend_w) { |
| ZSTD_wildcopy(op, match, oend_w - op); |
| match += oend_w - op; |
| op = oend_w; |
| } |
| while (op < oMatchEnd) *op++ = *match++; |
| } else { |
| ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8); /* works even if matchLength < 8 */ |
| } |
| return sequenceLength; |
| } |
| |
| static void |
| ZSTD_initFseState(ZSTD_fseState* DStatePtr, BIT_DStream_t* bitD, const ZSTD_seqSymbol* dt) |
| { |
| const void* ptr = dt; |
| const ZSTD_seqSymbol_header* const DTableH = (const ZSTD_seqSymbol_header*)ptr; |
| DStatePtr->state = BIT_readBits(bitD, DTableH->tableLog); |
| DEBUGLOG(6, "ZSTD_initFseState : val=%u using %u bits", |
| (U32)DStatePtr->state, DTableH->tableLog); |
| BIT_reloadDStream(bitD); |
| DStatePtr->table = dt + 1; |
| } |
| |
| FORCE_INLINE_TEMPLATE void |
| ZSTD_updateFseState(ZSTD_fseState* DStatePtr, BIT_DStream_t* bitD) |
| { |
| ZSTD_seqSymbol const DInfo = DStatePtr->table[DStatePtr->state]; |
| U32 const nbBits = DInfo.nbBits; |
| size_t const lowBits = BIT_readBits(bitD, nbBits); |
| DStatePtr->state = DInfo.nextState + lowBits; |
| } |
| |
| /* We need to add at most (ZSTD_WINDOWLOG_MAX_32 - 1) bits to read the maximum |
| * offset bits. But we can only read at most (STREAM_ACCUMULATOR_MIN_32 - 1) |
| * bits before reloading. This value is the maximum number of bytes we read |
| * after reloading when we are decoding long offsets. |
| */ |
| #define LONG_OFFSETS_MAX_EXTRA_BITS_32 \ |
| (ZSTD_WINDOWLOG_MAX_32 > STREAM_ACCUMULATOR_MIN_32 \ |
| ? ZSTD_WINDOWLOG_MAX_32 - STREAM_ACCUMULATOR_MIN_32 \ |
| : 0) |
| |
| typedef enum { ZSTD_lo_isRegularOffset, ZSTD_lo_isLongOffset=1 } ZSTD_longOffset_e; |
| |
| #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG |
| FORCE_INLINE_TEMPLATE seq_t |
| ZSTD_decodeSequence(seqState_t* seqState, const ZSTD_longOffset_e longOffsets) |
| { |
| seq_t seq; |
| U32 const llBits = seqState->stateLL.table[seqState->stateLL.state].nbAdditionalBits; |
| U32 const mlBits = seqState->stateML.table[seqState->stateML.state].nbAdditionalBits; |
| U32 const ofBits = seqState->stateOffb.table[seqState->stateOffb.state].nbAdditionalBits; |
| U32 const totalBits = llBits+mlBits+ofBits; |
| U32 const llBase = seqState->stateLL.table[seqState->stateLL.state].baseValue; |
| U32 const mlBase = seqState->stateML.table[seqState->stateML.state].baseValue; |
| U32 const ofBase = seqState->stateOffb.table[seqState->stateOffb.state].baseValue; |
| |
| /* sequence */ |
| { size_t offset; |
| if (!ofBits) |
| offset = 0; |
| else { |
| ZSTD_STATIC_ASSERT(ZSTD_lo_isLongOffset == 1); |
| ZSTD_STATIC_ASSERT(LONG_OFFSETS_MAX_EXTRA_BITS_32 == 5); |
| assert(ofBits <= MaxOff); |
| if (MEM_32bits() && longOffsets && (ofBits >= STREAM_ACCUMULATOR_MIN_32)) { |
| U32 const extraBits = ofBits - MIN(ofBits, 32 - seqState->DStream.bitsConsumed); |
| offset = ofBase + (BIT_readBitsFast(&seqState->DStream, ofBits - extraBits) << extraBits); |
| BIT_reloadDStream(&seqState->DStream); |
| if (extraBits) offset += BIT_readBitsFast(&seqState->DStream, extraBits); |
| assert(extraBits <= LONG_OFFSETS_MAX_EXTRA_BITS_32); /* to avoid another reload */ |
| } else { |
| offset = ofBase + BIT_readBitsFast(&seqState->DStream, ofBits/*>0*/); /* <= (ZSTD_WINDOWLOG_MAX-1) bits */ |
| if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream); |
| } |
| } |
| |
| if (ofBits <= 1) { |
| offset += (llBase==0); |
| if (offset) { |
| size_t temp = (offset==3) ? seqState->prevOffset[0] - 1 : seqState->prevOffset[offset]; |
| temp += !temp; /* 0 is not valid; input is corrupted; force offset to 1 */ |
| if (offset != 1) seqState->prevOffset[2] = seqState->prevOffset[1]; |
| seqState->prevOffset[1] = seqState->prevOffset[0]; |
| seqState->prevOffset[0] = offset = temp; |
| } else { /* offset == 0 */ |
| offset = seqState->prevOffset[0]; |
| } |
| } else { |
| seqState->prevOffset[2] = seqState->prevOffset[1]; |
| seqState->prevOffset[1] = seqState->prevOffset[0]; |
| seqState->prevOffset[0] = offset; |
| } |
| seq.offset = offset; |
| } |
| |
| seq.matchLength = mlBase |
| + ((mlBits>0) ? BIT_readBitsFast(&seqState->DStream, mlBits/*>0*/) : 0); /* <= 16 bits */ |
| if (MEM_32bits() && (mlBits+llBits >= STREAM_ACCUMULATOR_MIN_32-LONG_OFFSETS_MAX_EXTRA_BITS_32)) |
| BIT_reloadDStream(&seqState->DStream); |
| if (MEM_64bits() && (totalBits >= STREAM_ACCUMULATOR_MIN_64-(LLFSELog+MLFSELog+OffFSELog))) |
| BIT_reloadDStream(&seqState->DStream); |
| /* Ensure there are enough bits to read the rest of data in 64-bit mode. */ |
| ZSTD_STATIC_ASSERT(16+LLFSELog+MLFSELog+OffFSELog < STREAM_ACCUMULATOR_MIN_64); |
| |
| seq.litLength = llBase |
| + ((llBits>0) ? BIT_readBitsFast(&seqState->DStream, llBits/*>0*/) : 0); /* <= 16 bits */ |
| if (MEM_32bits()) |
| BIT_reloadDStream(&seqState->DStream); |
| |
| DEBUGLOG(6, "seq: litL=%u, matchL=%u, offset=%u", |
| (U32)seq.litLength, (U32)seq.matchLength, (U32)seq.offset); |
| |
| /* ANS state update */ |
| ZSTD_updateFseState(&seqState->stateLL, &seqState->DStream); /* <= 9 bits */ |
| ZSTD_updateFseState(&seqState->stateML, &seqState->DStream); /* <= 9 bits */ |
| if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream); /* <= 18 bits */ |
| ZSTD_updateFseState(&seqState->stateOffb, &seqState->DStream); /* <= 8 bits */ |
| |
| return seq; |
| } |
| |
| FORCE_INLINE_TEMPLATE size_t |
| ZSTD_decompressSequences_body( ZSTD_DCtx* dctx, |
| void* dst, size_t maxDstSize, |
| const void* seqStart, size_t seqSize, int nbSeq, |
| const ZSTD_longOffset_e isLongOffset) |
| { |
| const BYTE* ip = (const BYTE*)seqStart; |
| const BYTE* const iend = ip + seqSize; |
| BYTE* const ostart = (BYTE* const)dst; |
| BYTE* const oend = ostart + maxDstSize; |
| BYTE* op = ostart; |
| const BYTE* litPtr = dctx->litPtr; |
| const BYTE* const litEnd = litPtr + dctx->litSize; |
| const BYTE* const prefixStart = (const BYTE*) (dctx->prefixStart); |
| const BYTE* const vBase = (const BYTE*) (dctx->virtualStart); |
| const BYTE* const dictEnd = (const BYTE*) (dctx->dictEnd); |
| DEBUGLOG(5, "ZSTD_decompressSequences_body"); |
| |
| /* Regen sequences */ |
| if (nbSeq) { |
| seqState_t seqState; |
| dctx->fseEntropy = 1; |
| { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; } |
| RETURN_ERROR_IF( |
| ERR_isError(BIT_initDStream(&seqState.DStream, ip, iend-ip)), |
| corruption_detected); |
| ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr); |
| ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr); |
| ZSTD_initFseState(&seqState.stateML, &seqState.DStream, dctx->MLTptr); |
| |
| for ( ; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && nbSeq ; ) { |
| nbSeq--; |
| { seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset); |
| size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litEnd, prefixStart, vBase, dictEnd); |
| DEBUGLOG(6, "regenerated sequence size : %u", (U32)oneSeqSize); |
| if (ZSTD_isError(oneSeqSize)) return oneSeqSize; |
| op += oneSeqSize; |
| } } |
| |
| /* check if reached exact end */ |
| DEBUGLOG(5, "ZSTD_decompressSequences_body: after decode loop, remaining nbSeq : %i", nbSeq); |
| RETURN_ERROR_IF(nbSeq, corruption_detected); |
| /* save reps for next block */ |
| { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) dctx->entropy.rep[i] = (U32)(seqState.prevOffset[i]); } |
| } |
| |
| /* last literal segment */ |
| { size_t const lastLLSize = litEnd - litPtr; |
| RETURN_ERROR_IF(lastLLSize > (size_t)(oend-op), dstSize_tooSmall); |
| memcpy(op, litPtr, lastLLSize); |
| op += lastLLSize; |
| } |
| |
| return op-ostart; |
| } |
| |
| static size_t |
| ZSTD_decompressSequences_default(ZSTD_DCtx* dctx, |
| void* dst, size_t maxDstSize, |
| const void* seqStart, size_t seqSize, int nbSeq, |
| const ZSTD_longOffset_e isLongOffset) |
| { |
| return ZSTD_decompressSequences_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); |
| } |
| #endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG */ |
| |
| |
| |
| #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT |
| FORCE_INLINE_TEMPLATE seq_t |
| ZSTD_decodeSequenceLong(seqState_t* seqState, ZSTD_longOffset_e const longOffsets) |
| { |
| seq_t seq; |
| U32 const llBits = seqState->stateLL.table[seqState->stateLL.state].nbAdditionalBits; |
| U32 const mlBits = seqState->stateML.table[seqState->stateML.state].nbAdditionalBits; |
| U32 const ofBits = seqState->stateOffb.table[seqState->stateOffb.state].nbAdditionalBits; |
| U32 const totalBits = llBits+mlBits+ofBits; |
| U32 const llBase = seqState->stateLL.table[seqState->stateLL.state].baseValue; |
| U32 const mlBase = seqState->stateML.table[seqState->stateML.state].baseValue; |
| U32 const ofBase = seqState->stateOffb.table[seqState->stateOffb.state].baseValue; |
| |
| /* sequence */ |
| { size_t offset; |
| if (!ofBits) |
| offset = 0; |
| else { |
| ZSTD_STATIC_ASSERT(ZSTD_lo_isLongOffset == 1); |
| ZSTD_STATIC_ASSERT(LONG_OFFSETS_MAX_EXTRA_BITS_32 == 5); |
| assert(ofBits <= MaxOff); |
| if (MEM_32bits() && longOffsets) { |
| U32 const extraBits = ofBits - MIN(ofBits, STREAM_ACCUMULATOR_MIN_32-1); |
| offset = ofBase + (BIT_readBitsFast(&seqState->DStream, ofBits - extraBits) << extraBits); |
| if (MEM_32bits() || extraBits) BIT_reloadDStream(&seqState->DStream); |
| if (extraBits) offset += BIT_readBitsFast(&seqState->DStream, extraBits); |
| } else { |
| offset = ofBase + BIT_readBitsFast(&seqState->DStream, ofBits); /* <= (ZSTD_WINDOWLOG_MAX-1) bits */ |
| if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream); |
| } |
| } |
| |
| if (ofBits <= 1) { |
| offset += (llBase==0); |
| if (offset) { |
| size_t temp = (offset==3) ? seqState->prevOffset[0] - 1 : seqState->prevOffset[offset]; |
| temp += !temp; /* 0 is not valid; input is corrupted; force offset to 1 */ |
| if (offset != 1) seqState->prevOffset[2] = seqState->prevOffset[1]; |
| seqState->prevOffset[1] = seqState->prevOffset[0]; |
| seqState->prevOffset[0] = offset = temp; |
| } else { |
| offset = seqState->prevOffset[0]; |
| } |
| } else { |
| seqState->prevOffset[2] = seqState->prevOffset[1]; |
| seqState->prevOffset[1] = seqState->prevOffset[0]; |
| seqState->prevOffset[0] = offset; |
| } |
| seq.offset = offset; |
| } |
| |
| seq.matchLength = mlBase + ((mlBits>0) ? BIT_readBitsFast(&seqState->DStream, mlBits) : 0); /* <= 16 bits */ |
| if (MEM_32bits() && (mlBits+llBits >= STREAM_ACCUMULATOR_MIN_32-LONG_OFFSETS_MAX_EXTRA_BITS_32)) |
| BIT_reloadDStream(&seqState->DStream); |
| if (MEM_64bits() && (totalBits >= STREAM_ACCUMULATOR_MIN_64-(LLFSELog+MLFSELog+OffFSELog))) |
| BIT_reloadDStream(&seqState->DStream); |
| /* Verify that there is enough bits to read the rest of the data in 64-bit mode. */ |
| ZSTD_STATIC_ASSERT(16+LLFSELog+MLFSELog+OffFSELog < STREAM_ACCUMULATOR_MIN_64); |
| |
| seq.litLength = llBase + ((llBits>0) ? BIT_readBitsFast(&seqState->DStream, llBits) : 0); /* <= 16 bits */ |
| if (MEM_32bits()) |
| BIT_reloadDStream(&seqState->DStream); |
| |
| { size_t const pos = seqState->pos + seq.litLength; |
| const BYTE* const matchBase = (seq.offset > pos) ? seqState->dictEnd : seqState->prefixStart; |
| seq.match = matchBase + pos - seq.offset; /* note : this operation can overflow when seq.offset is really too large, which can only happen when input is corrupted. |
| * No consequence though : no memory access will occur, overly large offset will be detected in ZSTD_execSequenceLong() */ |
| seqState->pos = pos + seq.matchLength; |
| } |
| |
| /* ANS state update */ |
| ZSTD_updateFseState(&seqState->stateLL, &seqState->DStream); /* <= 9 bits */ |
| ZSTD_updateFseState(&seqState->stateML, &seqState->DStream); /* <= 9 bits */ |
| if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream); /* <= 18 bits */ |
| ZSTD_updateFseState(&seqState->stateOffb, &seqState->DStream); /* <= 8 bits */ |
| |
| return seq; |
| } |
| |
| FORCE_INLINE_TEMPLATE size_t |
| ZSTD_decompressSequencesLong_body( |
| ZSTD_DCtx* dctx, |
| void* dst, size_t maxDstSize, |
| const void* seqStart, size_t seqSize, int nbSeq, |
| const ZSTD_longOffset_e isLongOffset) |
| { |
| const BYTE* ip = (const BYTE*)seqStart; |
| const BYTE* const iend = ip + seqSize; |
| BYTE* const ostart = (BYTE* const)dst; |
| BYTE* const oend = ostart + maxDstSize; |
| BYTE* op = ostart; |
| const BYTE* litPtr = dctx->litPtr; |
| const BYTE* const litEnd = litPtr + dctx->litSize; |
| const BYTE* const prefixStart = (const BYTE*) (dctx->prefixStart); |
| const BYTE* const dictStart = (const BYTE*) (dctx->virtualStart); |
| const BYTE* const dictEnd = (const BYTE*) (dctx->dictEnd); |
| |
| /* Regen sequences */ |
| if (nbSeq) { |
| #define STORED_SEQS 4 |
| #define STORED_SEQS_MASK (STORED_SEQS-1) |
| #define ADVANCED_SEQS 4 |
| seq_t sequences[STORED_SEQS]; |
| int const seqAdvance = MIN(nbSeq, ADVANCED_SEQS); |
| seqState_t seqState; |
| int seqNb; |
| dctx->fseEntropy = 1; |
| { int i; for (i=0; i<ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; } |
| seqState.prefixStart = prefixStart; |
| seqState.pos = (size_t)(op-prefixStart); |
| seqState.dictEnd = dictEnd; |
| assert(iend >= ip); |
| RETURN_ERROR_IF( |
| ERR_isError(BIT_initDStream(&seqState.DStream, ip, iend-ip)), |
| corruption_detected); |
| ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr); |
| ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr); |
| ZSTD_initFseState(&seqState.stateML, &seqState.DStream, dctx->MLTptr); |
| |
| /* prepare in advance */ |
| for (seqNb=0; (BIT_reloadDStream(&seqState.DStream) <= BIT_DStream_completed) && (seqNb<seqAdvance); seqNb++) { |
| sequences[seqNb] = ZSTD_decodeSequenceLong(&seqState, isLongOffset); |
| PREFETCH_L1(sequences[seqNb].match); PREFETCH_L1(sequences[seqNb].match + sequences[seqNb].matchLength - 1); /* note : it's safe to invoke PREFETCH() on any memory address, including invalid ones */ |
| } |
| RETURN_ERROR_IF(seqNb<seqAdvance, corruption_detected); |
| |
| /* decode and decompress */ |
| for ( ; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && (seqNb<nbSeq) ; seqNb++) { |
| seq_t const sequence = ZSTD_decodeSequenceLong(&seqState, isLongOffset); |
| size_t const oneSeqSize = ZSTD_execSequenceLong(op, oend, sequences[(seqNb-ADVANCED_SEQS) & STORED_SEQS_MASK], &litPtr, litEnd, prefixStart, dictStart, dictEnd); |
| if (ZSTD_isError(oneSeqSize)) return oneSeqSize; |
| PREFETCH_L1(sequence.match); PREFETCH_L1(sequence.match + sequence.matchLength - 1); /* note : it's safe to invoke PREFETCH() on any memory address, including invalid ones */ |
| sequences[seqNb & STORED_SEQS_MASK] = sequence; |
| op += oneSeqSize; |
| } |
| RETURN_ERROR_IF(seqNb<nbSeq, corruption_detected); |
| |
| /* finish queue */ |
| seqNb -= seqAdvance; |
| for ( ; seqNb<nbSeq ; seqNb++) { |
| size_t const oneSeqSize = ZSTD_execSequenceLong(op, oend, sequences[seqNb&STORED_SEQS_MASK], &litPtr, litEnd, prefixStart, dictStart, dictEnd); |
| if (ZSTD_isError(oneSeqSize)) return oneSeqSize; |
| op += oneSeqSize; |
| } |
| |
| /* save reps for next block */ |
| { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) dctx->entropy.rep[i] = (U32)(seqState.prevOffset[i]); } |
| } |
| |
| /* last literal segment */ |
| { size_t const lastLLSize = litEnd - litPtr; |
| RETURN_ERROR_IF(lastLLSize > (size_t)(oend-op), dstSize_tooSmall); |
| memcpy(op, litPtr, lastLLSize); |
| op += lastLLSize; |
| } |
| |
| return op-ostart; |
| } |
| |
| static size_t |
| ZSTD_decompressSequencesLong_default(ZSTD_DCtx* dctx, |
| void* dst, size_t maxDstSize, |
| const void* seqStart, size_t seqSize, int nbSeq, |
| const ZSTD_longOffset_e isLongOffset) |
| { |
| return ZSTD_decompressSequencesLong_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); |
| } |
| #endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT */ |
| |
| |
| |
| #if DYNAMIC_BMI2 |
| |
| #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG |
| static TARGET_ATTRIBUTE("bmi2") size_t |
| ZSTD_decompressSequences_bmi2(ZSTD_DCtx* dctx, |
| void* dst, size_t maxDstSize, |
| const void* seqStart, size_t seqSize, int nbSeq, |
| const ZSTD_longOffset_e isLongOffset) |
| { |
| return ZSTD_decompressSequences_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); |
| } |
| #endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG */ |
| |
| #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT |
| static TARGET_ATTRIBUTE("bmi2") size_t |
| ZSTD_decompressSequencesLong_bmi2(ZSTD_DCtx* dctx, |
| void* dst, size_t maxDstSize, |
| const void* seqStart, size_t seqSize, int nbSeq, |
| const ZSTD_longOffset_e isLongOffset) |
| { |
| return ZSTD_decompressSequencesLong_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); |
| } |
| #endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT */ |
| |
| #endif /* DYNAMIC_BMI2 */ |
| |
| typedef size_t (*ZSTD_decompressSequences_t)( |
| ZSTD_DCtx* dctx, |
| void* dst, size_t maxDstSize, |
| const void* seqStart, size_t seqSize, int nbSeq, |
| const ZSTD_longOffset_e isLongOffset); |
| |
| #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG |
| static size_t |
| ZSTD_decompressSequences(ZSTD_DCtx* dctx, void* dst, size_t maxDstSize, |
| const void* seqStart, size_t seqSize, int nbSeq, |
| const ZSTD_longOffset_e isLongOffset) |
| { |
| DEBUGLOG(5, "ZSTD_decompressSequences"); |
| #if DYNAMIC_BMI2 |
| if (dctx->bmi2) { |
| return ZSTD_decompressSequences_bmi2(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); |
| } |
| #endif |
| return ZSTD_decompressSequences_default(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); |
| } |
| #endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG */ |
| |
| |
| #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT |
| /* ZSTD_decompressSequencesLong() : |
| * decompression function triggered when a minimum share of offsets is considered "long", |
| * aka out of cache. |
| * note : "long" definition seems overloaded here, sometimes meaning "wider than bitstream register", and sometimes meaning "farther than memory cache distance". |
| * This function will try to mitigate main memory latency through the use of prefetching */ |
| static size_t |
| ZSTD_decompressSequencesLong(ZSTD_DCtx* dctx, |
| void* dst, size_t maxDstSize, |
| const void* seqStart, size_t seqSize, int nbSeq, |
| const ZSTD_longOffset_e isLongOffset) |
| { |
| DEBUGLOG(5, "ZSTD_decompressSequencesLong"); |
| #if DYNAMIC_BMI2 |
| if (dctx->bmi2) { |
| return ZSTD_decompressSequencesLong_bmi2(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); |
| } |
| #endif |
| return ZSTD_decompressSequencesLong_default(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset); |
| } |
| #endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT */ |
| |
| |
| |
| #if !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \ |
| !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG) |
| /* ZSTD_getLongOffsetsShare() : |
| * condition : offTable must be valid |
| * @return : "share" of long offsets (arbitrarily defined as > (1<<23)) |
| * compared to maximum possible of (1<<OffFSELog) */ |
| static unsigned |
| ZSTD_getLongOffsetsShare(const ZSTD_seqSymbol* offTable) |
| { |
| const void* ptr = offTable; |
| U32 const tableLog = ((const ZSTD_seqSymbol_header*)ptr)[0].tableLog; |
| const ZSTD_seqSymbol* table = offTable + 1; |
| U32 const max = 1 << tableLog; |
| U32 u, total = 0; |
| DEBUGLOG(5, "ZSTD_getLongOffsetsShare: (tableLog=%u)", tableLog); |
| |
| assert(max <= (1 << OffFSELog)); /* max not too large */ |
| for (u=0; u<max; u++) { |
| if (table[u].nbAdditionalBits > 22) total += 1; |
| } |
| |
| assert(tableLog <= OffFSELog); |
| total <<= (OffFSELog - tableLog); /* scale to OffFSELog */ |
| |
| return total; |
| } |
| #endif |
| |
| |
| size_t |
| ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx, |
| void* dst, size_t dstCapacity, |
| const void* src, size_t srcSize, const int frame) |
| { /* blockType == blockCompressed */ |
| const BYTE* ip = (const BYTE*)src; |
| /* isLongOffset must be true if there are long offsets. |
| * Offsets are long if they are larger than 2^STREAM_ACCUMULATOR_MIN. |
| * We don't expect that to be the case in 64-bit mode. |
| * In block mode, window size is not known, so we have to be conservative. |
| * (note: but it could be evaluated from current-lowLimit) |
| */ |
| ZSTD_longOffset_e const isLongOffset = (ZSTD_longOffset_e)(MEM_32bits() && (!frame || (dctx->fParams.windowSize > (1ULL << STREAM_ACCUMULATOR_MIN)))); |
| DEBUGLOG(5, "ZSTD_decompressBlock_internal (size : %u)", (U32)srcSize); |
| |
| RETURN_ERROR_IF(srcSize >= ZSTD_BLOCKSIZE_MAX, srcSize_wrong); |
| |
| /* Decode literals section */ |
| { size_t const litCSize = ZSTD_decodeLiteralsBlock(dctx, src, srcSize); |
| DEBUGLOG(5, "ZSTD_decodeLiteralsBlock : %u", (U32)litCSize); |
| if (ZSTD_isError(litCSize)) return litCSize; |
| ip += litCSize; |
| srcSize -= litCSize; |
| } |
| |
| /* Build Decoding Tables */ |
| { |
| /* These macros control at build-time which decompressor implementation |
| * we use. If neither is defined, we do some inspection and dispatch at |
| * runtime. |
| */ |
| #if !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \ |
| !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG) |
| int usePrefetchDecoder = dctx->ddictIsCold; |
| #endif |
| int nbSeq; |
| size_t const seqHSize = ZSTD_decodeSeqHeaders(dctx, &nbSeq, ip, srcSize); |
| if (ZSTD_isError(seqHSize)) return seqHSize; |
| ip += seqHSize; |
| srcSize -= seqHSize; |
| |
| #if !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \ |
| !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG) |
| if ( !usePrefetchDecoder |
| && (!frame || (dctx->fParams.windowSize > (1<<24))) |
| && (nbSeq>ADVANCED_SEQS) ) { /* could probably use a larger nbSeq limit */ |
| U32 const shareLongOffsets = ZSTD_getLongOffsetsShare(dctx->OFTptr); |
| U32 const minShare = MEM_64bits() ? 7 : 20; /* heuristic values, correspond to 2.73% and 7.81% */ |
| usePrefetchDecoder = (shareLongOffsets >= minShare); |
| } |
| #endif |
| |
| dctx->ddictIsCold = 0; |
| |
| #if !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \ |
| !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG) |
| if (usePrefetchDecoder) |
| #endif |
| #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT |
| return ZSTD_decompressSequencesLong(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset); |
| #endif |
| |
| #ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG |
| /* else */ |
| return ZSTD_decompressSequences(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset); |
| #endif |
| } |
| } |
| |
| |
| size_t ZSTD_decompressBlock(ZSTD_DCtx* dctx, |
| void* dst, size_t dstCapacity, |
| const void* src, size_t srcSize) |
| { |
| size_t dSize; |
| ZSTD_checkContinuity(dctx, dst); |
| dSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize, /* frame */ 0); |
| dctx->previousDstEnd = (char*)dst + dSize; |
| return dSize; |
| } |